// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// http://github.com/jskeet/dotnet-protobufs/
// Original C++/Java/Python code:
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
using System;
using System.Collections;
using System.Collections.Generic;

namespace Google.ProtocolBuffers.Collections {
  /// <summary>
  /// Read-only wrapper around another dictionary.
  /// </summary>
  public sealed class ReadOnlyDictionary<TKey, TValue> : IDictionary<TKey, TValue> {
    readonly IDictionary<TKey, TValue> wrapped;

    public ReadOnlyDictionary(IDictionary<TKey, TValue> wrapped) {
      this.wrapped = wrapped;
    }

    public void Add(TKey key, TValue value) {
      throw new InvalidOperationException();
    }

    public bool ContainsKey(TKey key) {
      return wrapped.ContainsKey(key);
    }

    public ICollection<TKey> Keys {
      get { return wrapped.Keys; }
    }

    public bool Remove(TKey key) {
      throw new InvalidOperationException();
    }

    public bool TryGetValue(TKey key, out TValue value) {
      return wrapped.TryGetValue(key, out value);
    }

    public ICollection<TValue> Values {
      get { return wrapped.Values; }
    }

    public TValue this[TKey key] {
      get {
        return wrapped[key];
      }
      set {
        throw new InvalidOperationException();
      }
    }

    public void Add(KeyValuePair<TKey, TValue> item) {
      throw new InvalidOperationException();
    }

    public void Clear() {
      throw new InvalidOperationException();
    }

    public bool Contains(KeyValuePair<TKey, TValue> item) {
      return wrapped.Contains(item);
    }

    public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex) {
      wrapped.CopyTo(array, arrayIndex);
    }

    public int Count {
      get { return wrapped.Count; }
    }

    public bool IsReadOnly {
      get { return true; }
    }

    public bool Remove(KeyValuePair<TKey, TValue> item) {
      throw new InvalidOperationException();
    }

    public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator() {
      return wrapped.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator() {
      return ((IEnumerable) wrapped).GetEnumerator();
    }

    public override bool Equals(object obj) {
      return wrapped.Equals(obj);
    }

    public override int GetHashCode() {
      return wrapped.GetHashCode();
    }

    public override string ToString() {
      return wrapped.ToString();
    }
  }
}
